帮助文件目录语法: if(表达式) 语句 if(表达式)语句 1 else 语句 2 if (表达式 1) 语句 1 else if(表达式 2)语句 2 else if(表达式 3)语句 3 else if(表达式 m)语句 m else 语句 n switch(表达式) { case 常量表达式 1:语句 1 case 常量表达式 2:语句 2 ┋ case 常量表达式 n:语句 n default :语句 n+1 } while (表达式) 语句; do 语句 while(表达式); for(表达式 1;表达式 2;表达式 3) 语句 break; continue;附录 C ASCII 编码对比表ASCII 值字符ASCII 值字符ASCII 值字符DecimaHexDecimalHexDecimalHexl000000NUL 020014DC4( ^T)040028(001001SOH (^A)021015NAK( ^U)041029)002 002STX (^B)022016SYN( ^V)04202A*003003ETX ( ^C)023017ETB(^W)04302B+ 004004EOT (^D)024018CAN( ^X)04402C , 005005ENQ (^E)025019EM(^Y)04502D — 006006ACK ( ^F)02601ASUB(^Z)04602E.007007BEL (Bell)02701BESC04702F/008008BS (^H)02801CFS0480300009009HT (^I)02901DGS049031101000ALF (^J)03001ERS050032201100BVT (^K)03101FUS051033301200CFF (^L)032020( 空格)052034401300DCR (^M)033021!053035501400ESO (^N)034022 " 054036601500FSI ( ^O)035023#0550377016010DLE (^P)036024$ 0560388017011DC1 (^Q) 037025%0570399018012DC2 ( ^R)038026&05803A019013DC3 (^S)039027’ 05903B ASCII 值字符ASCII 值字符ASCII 值字符DecimalHexDecimalHexDecimalHex06003C< 099063c13808Aè06103D=100064d13908Bï062 03E〉101065e14008Cî06303F?102066f14108Dì 064040@103067g14208EÄ 065041A104068h14308FÅ 066042B105069i144090É067043C10606A j 145091æ068044D10706Bk146092Æ069045E10806Cl 147093ô070046F10906Dm148094ö071047G11006En149095ò072048H11106Fo 150096û073049I112070p151097ù07404AJ113071q152098ÿ07504BK114072r153099Ö07604CL115073s15409AÜ07704DM 116074t15509Bø07804EN117075u15609C£07904FO118076v15709DØ080050P119077w15809E×081051Q120078x15909Fƒ082052R121079y1600A0á083053S12207Az1610A1í084054T12307B{1620A2ó085055U12407C|1630A3ú086056V12507D}1640A4ñ087057W12607E~ 1650A5Ñ088058X12707FDE...